Module 2 chapter 6

advertisement
Module 2: Information
Technology Infrastructure
Chapter 6:
Telecommunications,
Internet and Wireless
Technology
Learning Objectives
• Identify the telecommunication media and hardware
required for transmission
• Identify the network types and key networking
technologies (including protocols)
• Discuss the principle technologies and standards for
wireless networking
• Describe several telecommunication applications
that orgs benefit from today
• Discuss how Internet works and its support for
communications and e-business
Intro to Telecommunications
• Telecommunication
– Electronic transmission of signals for communication
– The general model of telecommunication consists of
•
•
•
•
The sending device
The medium
The communication device
The receiving unit
Intro to telecommunications
• Transmission medium
– Any material substance that carries an electronic signal to support
communications between sending and receiving devices
– Divided into one or more communication channels
– Classified as simplex, half duplex, full duplex
– Characteristics:
•
•
•
•
•
Bandwidth: rate at which data is exchanged (bps)
Higher bandwidth, more channel transmits
Broadband
Latency: time it takes a signal to travel from one location to another
Best combo: high bandwidth, low latency
Intro to telecommunications
• Physical transmission medium
Media Type
Description
Advantages
Disadvantages
Twisted pair
cable
Twisted pair of
copper wires,
insulated
Used for
telephone
services, widely
available
Transmission
speed and
distance
limitation
Coaxial Cable
Inner conductor
wire surrounded
by insulation
Cleaner and
faster data
transfer than
twisted pair
More expensive
than twisted pair
Fiber-Optic cable
Extremely thin
glass strands
bound together
in a sheathing,
uses light to
transmit
Less diameter,
less distortion
and high
transmission rate
Expensive to
purchase and
install
Intro to telecommunications
• Wireless transmission medium
– Microwave
– Radio
– Infrared
Intro to telecommunications
• Telecommunication Hardware
– Modem
• Special device that converts digital signals to analog signals (modulation)
and vice versa (demodulation)
• PC modem, cable modem, DSL modem
– Hub
• Device that connect network components, sending a packet of data to all
other connected devices
– Switch
• Smarter than hub, forward data to specific destination
– Network Interface Card
• Network interface device, connection medium for linking network
components
Intro to telecommunications
• Telecommunication Hardware
– Router
– WAP
Computer Network
• A network consists of two or more connected
computers
• A simple network contains:
–
–
–
–
–
–
Client computer
Dedicated server
Network interfaces
Connection medium
Network operating system
Hub/switch
Computer Network
Wired Network with Hub/Switch
Two router Network
Hybrid Network
Computer Network
• Types of Networks
– Local Area Networks (LAN): connects computer systems and devices
within a small area, typically they are wired into office buildings
• Computers must be equipped with the correct interface
• Client/Server architecture: One computer is dedicated network file server,
providing access to resources
• Ethernet: LAN standard for physical medium (10 Mbps)
• Fast Ethernet (100Mps), Gigabit Ethernet (1 Gbps)
• Peer-to-peer architecture: used in very small networks, different computers
can exchange data by direct access and also peripheral devices. Useful for
small businesses
– Metropolitan Area Networks (MAN): connects computers systems
within a campus or a city
• Range of 30-90 miles
Computer Network
• Types of Networks
– Wide Area Networks (WAN):International Networks: connects large
geographical regions
• Internet – world’s largest WAN
– Mesh Networking: way to route communications among network nodes
by allowing for continuous connections and reconfiguration around
blocked paths
• Robust, if one node fails, others can still communicate
• Can be used to provide Internet access, secure connections to corporate netowrks and
VoIP calls
Key Digital Networking Technologies
• Client/Server computing
– Distributed computing model, some processing power on client
computers
– Linked to network to server computers, sets rules for communication,
provides every client with an address
• Packet Switching
– Slicing digital messages into packets, sending them over
communication paths, reassembling at destination
– Transmitted through routers
Key Digital Networking Technologies
• TCP/IP Connectivity
– Protocol: set of rules and procedures concerning transmission of
information between 2 points in a network
– Now only worldwide standard Transmission Control Protocol/Internet
Protocol (TCP/IP) is used with any kind of hardware for networking
– TCP: handles movement of data between computers, sequencing
packets and acknowledging sending
– IP: delivery of packets and reassembling during transmission
Wireless Communication
• Advantages:
• Helps businesses stay in touch with customers, suppliers,
partners
• Provides flexible arrangements for organizing work
• Help create new products, services, sales channels
• Provide easier access to remote corporate areas
Wireless Communication Standards
• Bluetooth
–
–
–
–
Wireless N/W standard, creates PAN
Range: 10m, 722Kbps (2.4Ghz)
Useful for battery powered devices (printers, Keyboard)
FedEx: signals transmitted from handheld devices through bluetooth
• Wi-Fi (802.11)
–
–
–
–
Standard for wireless LAN and wireless Internet access
Range: 30-5-m, 11Mbps-54Mbps (2.4Ghz)
Use: creating ‘hotspots’
802.11 n is the fastest ( 100Mbps) based on the MIMO( multiple
input/multiple output)
Wireless Communication Standards
• WiMAX
–
–
–
–
Worldwide Interoperability for Microwave Access)
Range: 31 miles, 75Mbps
Use: areas where difficult to install broadband or Wi-Fi
Connectivity provided by WiMAX towers
Wireless Communication Standards
• RFID
– Standard for radio signals to communicate with a tag
– Use: tracking movement of goods through supply chain
– RFID Tag
• embedded microchip and antenna
• Active: battery powered, send data automatically, expensive
• Passive: powered by the signals from reader, lighter, less expensive
– RFID Reader
• Reads tag, capturing the data, decodes it and send it over the network to the computer
• Reads data in its range
– Businesses need to update H/W and S/W to accommodate large data
from RFID
– SAP, Oracle offer RFID-ready versions for SCM applications
Cellular Network
• ITU developed standard for cellular networks
– To standardize and allow global roaming
• Mobile Communication standard
– Global System for Mobile Communication (GSM) and CDMA
– GPRS (General Packet Radio Service), EDGE, EVDO (Evolution Data
Optimized)
– Earlier for voice and small data
– 3G 144 Kbps to 2.4 Mbps
• Video, VoIP, graphics, rich media
– Next: 4G 100Mbps
Telecommunication and Network Applications
• Important Business applications include:
• Linking Pcs to Mainframes/Servers
• Voice Mail
– Send/receive store verbal messages
• Small Business Networks
– Create small networks with few devices easily
– Either WAP with modem or a combo device (router, firewall, hub)
• Filtering and encryption
• Electronic Document Distribution
– Send/receive digital documents
• Saves paper, access faster
Telecommunication and Network Applications
•
•
•
•
•
•
•
Call Centres
Telecommuting/Virtual Workers
Videoconferencing
Electronic Data Interchange (EDI)
Electronic Funds Transfer (EFT)
Distance Learning
Team Collaboration
Case Study: Delivering People More Efficiently
Through Telecommunications
• Crew Transportation Industry
– Shuttling crew members to train locations where they are needed
• Problem:
– Slow to adopt telecomm technologies
– Van drivers could not communicate with dispatcher while in route
– Railway company not happy
• RailCrewXpress
– Serving railways through technology platform
– Wireless telecommunication system that connects drivers with
dispatchers and company IS
– Tracks drivers, dynamic routing change, maintains history of routes and
driver times
– Data is analysed to optimize the efficiency of dispatches & routing
Case Study: Delivering People More Efficiently
Through Telecommunications
• Challenges
– Economical networking technologies
– Automatically switch between satellite and GPRS data transmission
– Intelligently decide how much info to send and when
• Next milestone
– RFID scanners to be installed in vans for tracking location
Case Study: Delivering People More Efficiently
Through Telecommunications
• Advantages
– Faster and efficient communication between drivers and dispatchers
– Happier railway companies, because they get accurate ETAs
– Flexibility to accept new trip orders and reroute quickly
• Real Time Monitoring
–
–
–
–
Providing time-relevant info for quick decision-making
View minute by minute info
Respond quickly to changing conditions
Analyse data for operational efficiency
Download